Net Revenue Retention (NRR) Calculator
Measure whether your existing customers grow on their own — NRR, GRR and net revenue churn from one cohort.
This free NRR calculator measures how much recurring revenue you keep from existing customers — expansion included. Enter a cohort's starting MRR plus the expansion, contraction and churn it experienced, and it returns net revenue retention, gross revenue retention and net revenue churn together, computed from the same numbers.
NRR (net revenue retention, also called NDR) is the metric investors quote most: above 100%, your existing book grows without a single new customer. Reading it next to GRR shows how much of that health is real retention versus expansion papering over losses.
How to calculate NRR
Fix a cohort of customers who were paying at the start of the period. Take their MRR then, add the expansion they generated, subtract contraction and churn, and divide by the starting MRR. New customers acquired during the period are deliberately excluded — NRR measures only the base you already had.
Compute GRR from the same cohort by leaving expansion out: it can never exceed 100% and shows the raw durability of the base. The gap between the two is exactly how much expansion contributes — a 105% NRR on a 90% GRR is a healthier business than the same NRR on an 80% GRR.
NRR = (starting MRR + expansion − contraction − churn) ÷ starting MRR × 100. GRR = (starting MRR − contraction − churn) ÷ starting MRR × 100.
A cohort starts at $20,000 MRR, adds $3,000 of expansion, loses $800 to downgrades and $1,200 to cancellations. NRR = ($20,000 + $3,000 − $2,000) ÷ $20,000 = 105%. GRR = 90%, and net revenue churn is −5% — negative churn.
Stop estimating. See your real numbers.
Connect Stripe and Bigdelta tracks your live MRR, ARR and churn automatically — no spreadsheets, no manual maths.